(* File: binary.griffin
 * Converts numbers into binary.
 * (C) 2014 Ariel Ortiz, ITESM CEM
 *)
 
var 
    option: string;
    num: integer; 

procedure Binary(
    num: integer;
    ): string;
    var
        result: string;
        remainder: integer;
    begin
        if num <= 0 then
            return "0";
        end;
        
        result := "";
        
        loop 
            remainder := num rem 2;
            result := CatStr(IntToStr(remainder), result);            
            num := num div 2;
            if num = 0 then exit; end;        
        end;
        
        return result;
    end;

program
    loop
        WrStr("Input a number: ");
        num := RdInt();

        WrStr("Conversion to binary of that number: ");
        WrStr(Binary(num));

        WrLn();

        WrStr("Convert another number? ");
        option := RdStr();

        if LenStr(option) = 0 then
            option := "N";
        else
            option := AtStr(option, 0);
        end;
        
        if CmpStr(option, "Y") <> 0 and CmpStr(option, "y") <> 0 then
            exit;
        end; 
    end;
end;